There are many methods of recognizing documents that are well known. They make use of an initial scanning step followed by a segmentation step in turn followed by an optical character recognition (OCR) step. The segmentation step (subdividing the document) can be applied to the entire document (a conventional “full page”) or to part of the document only.
Nevertheless, such a conventional method making it subsequently possible to index the document automatically can be envisaged only if the document to be recognized is not too complex. In addition, it is not applied to technical drawings. In this particular field, only the initial step of scanning is performed, with the steps of segmentation and recognition being replaced by a step that is performed directly by an operator and consisting in manually inputting the particular elements required for indexing the drawing, from one or more zones of the drawing (in practice present in the title block of the drawing).
It will be understood that under such circumstances, this becomes very tedious when it is necessary to index more than a dozen technical drawings, possibly of different types (i.e. with information blocks of different shapes). There thus exists, at present, an unsatisfied need for a method of indexing such drawings on the basis of automatic recognition.